Inside a conventional telecommunications equipment, a direct current voltage of −48 V or −60 V input from an office equipment room is used to provide power supply to a load in the telecommunications equipment, and a rated power supply current input from the office equipment room is limited, for example, a common rated power supply current is 32 A, 63 A, 80 A, or the like. The load in the telecommunications equipment may include a service board, a cooling fan, or the like. To ensure security of power supply, total power of loads connected to a power supply branch circuit cannot exceed a power supply capability of the power supply branch circuit, where Power supply capability of the power supply branch circuit=Power supply voltage of the branch circuit×Rated power supply current of the branch circuit×Derating coefficient. If the total power of the loads connected to the power supply branch circuit exceeds the power supply capability of the power supply branch circuit, multiple power supply inputs need to be led in from the office equipment room; and correspondingly, multiple power supply branch circuits need to be configured for the telecommunications equipment, and loads included in the telecommunications equipment also need to be sectioned, where one power supply input provides power supply to a load in each section.
For a telecommunications equipment with multiple sections, because there is no restriction on a specific slot into which a customer inserts a service board, generally, power distribution for all sections are already connected during initial configuration, to ensure that a service board can work normally regardless of the slot into which the service board is inserted. In this case, if the number of boards actually configured on the telecommunications equipment by a customer is relatively small, power supply resources provided to the telecommunications equipment by an office equipment room may be seriously wasted. To resolve the problem of a waste of power supply resources, when a telecommunications equipment includes several power supply branch circuits, in the prior art, a power supply unit is configured for each power supply branch circuit of the telecommunications equipment, and the power supply unit performs voltage regulation and conversion and current equalization control on a direct current voltage that is input by each power supply branch circuit; and connects a voltage that is output after conversion by the power supply unit, to form a power supply resource pool. All loads in a communication equipment obtain power from the power supply resource pool, so that sharing of power supply resources is implemented. When a relatively small number of service boards are configured in the telecommunications equipment, the number of power supply branch circuits and the number of corresponding power supply units may be reduced, to reduce a waste of power supply resources.
In the prior art, at least the following problem exists: Before providing power supply to a load in a telecommunications equipment, a power supply voltage led in from an office equipment room needs to be converted by a power supply unit. In this case, when total power of all loads connected to the telecommunications equipment is relatively large, more power supply branch circuits are configured for the telecommunications equipment, and a power supply unit must be configured for each power supply branch circuit, which leads to an increase in the number of power supply units, thereby increasing power supply costs.